The present invention relates to a new and distinct cultivar of Acer palmatum, and will be referred to hereafter by its cultivar name, ‘Ryusen’. ‘Ryusen’ is a deciduous tree grown for use as a landscape plant.
The new Acer was discovered in Kawaguchi City, Saitama, Japan as a naturally occurring whole plant mutant in a maple nursery in summer of 1990. The parent plants of the new Acer are unknown.
‘Ryusen’ is selected as unique for its true weeping habit. ‘Ryusen’ is grafted onto root-stock of Acer palmatum and then trained as an upright plant until a desirable height before allowing the plant to naturally weep. The branching emerge at about a 45° angle and then become pendant almost vertically. The species, Acer palmatum, has an upright habit. The closest comparison cultivar known to the inventor is Acer palmatum, ‘Jiro Shidare’ (not patented). ‘Jiro Shidare’ is similar to ‘Ryusen’ in having green foliage with a cascading habit, however the branches of ‘Jiro Shidare’ are initially upright and then cascade with an arching habit to form a tree with an open, rounded habit, the branches are not strictly pendant as they are for ‘Ryusen’.
Asexual reproduction of the new cultivar was first accomplished by grafting of terminal stem cuttings at Kawaguchi City, Saitama, Japan, by the inventor in 1996. The characteristics of this cultivar have been determined to be stable and are reproduced true to type in successive generations.